The use of a spray is known for street-cleaning purposes. The many spray nozzles on the beam are directed at the surface to be cleaned so as to loosen and wash away dirt thereon. The greater pressure and flow the greater is the cleaning and rinsing effect. As these two parameters grow, however, the reaction force against the spray beam also increases. It is therefore necessary to make the support for the sprayer beam very robust in order to compensate for these high pressures. In addition, it is necessary to support the sprayer beam on the surface relatively close to the washing location. When cleaning a wall or ceiling surface the problem is compounded considerably as it is necessary to provide a massive support and holding arrangement.